Plastic lifeboats

ABSTRACT

Ship&#39;&#39;s lifeboats with minimum of closely fitting parts made in symmetrical molds for left hand and right hand positions, each suitable for four different lifeboat types without change to molds. Major parts before final assembly comprising two subassembled sides with inner hull and hoisting bulkheads, two fairwater ends, one keel and sub-assembled seat-platform provision tanks. Simplefied hoisting gear is provided for simultaneous release of two hooks from their respective hoisting links.

I Unlted States Patent 1 1 1111 3,806,971

Elling Apr. 30, 1974 PLASTIC LIFEBOATS 2,453,463 11/1948 Sherman 9/3[76] Inventor: William E. Elling, 57 Bounty St.,

Metuchen, NJ 08840 Primary Etam1nerGeorge E. A. Halvosa AssistantExaminer-Randolph A. Reese [22] Filed: Aug. 30, 1972 [21 App]. No.:285,016 ABSTRACT Ships lifeboats with minimum of closely fitting parts52 us. (:1 9/3 9/6 9/45 made in Symmetrical mlds for left hand and right51 1111. C1. 13631; 9/02 hand Positions each suitable for four differentlifeboat [58] Field of Search 9/3 6 6.5 44 45 types without Changemolds- Parts before 1 6 final assembly comprising two sub-assembledsides with inner hull and hoisting bulkheads, two fairwater 56]References Cited ends, one keel and sub-assembled seat-platform provi-UNITED STATES PATENTS sion tanks. Simplefied hoisting gear is providedfor simultaneous release of two hooks from their respective 3,101,4908/1963 Jacobi 9/3 hoisting links 3,101,489 8/1963 Chance... 3,013,92212/1961 Fisher 9/3 8 Claims, 14 Drawing Figures SHEET 2 OF 4 lIIIIIII villullilii III IIIIIII ililli lla. IiIil IIIIII I SHEET 3 [1F 4 I" I-I-III-I PLASTIC LIFEBOATS This invention relates to new and usefulimprovements'in lifeboats for use on ships, complying in all respectswith the regulations of all of the principal maritime countries and, inparticular, with those of the United States.

The following are considerations valuable to the understanding of thisinvention:

A. In the design of ocean-going vessels it is important to save on thetop weight of the ship. Therefore, in the past, because of the weightfactor, lifeboats made of aluminum became gradually preferable to thoseof steel. Steel or aluminum were used, for instance, in lifeboatsdescribed in prior patents Elling U.S. Pat. No. 2,233,254 of Feb. 25,1941, Elling U.S. Pat. No. 2,328,437 of Aug. 31, 1943, and Elling U.S.Pat. No. 2,478,042 of Aug. 2, 1949, over which the present invention isan improvement in important aspects.

B. The advent, in recent years, of the use of plastic material in themanufacture of lifeboats has faced shipbuilders and ship operators witha choice betweeen aluminum lifeboats and lifeboats made offiberglassreinforced plastic hereinafter referred to as F-R P. Thechoice has been a difficult one because, although the cost of upkeep ofF-R P lifeboats with foamed flotation tanks is low in comparison withlifeboats having metal air tanks, the weight of present-day F-R Plifeboats has turned out to be nearly as great as that of steellifeboats. However, the weight of the FR P lifeboats of this inventionis equal to, or less than, the weight of presently built aluminumlifeboats. This and other advantages, disclosed hereinafter, will beunderstood and appreciated by those experienced in the art.

C. The term fiberglass-reinforced plastic (F-R P) is generally used inthe trade for hand lay-up of fiberglass cloth, fiberglass woven-rovingand fiberglass mat, after saturation with polyester resin.

D. Lifeboat construction has generally been a custom-built type ofprocedure. Parts are still installed or added one after the other withthe boat in upright position and with scaffolds in constant use. Workingwith polyester resins on large, unwieldy products can be extremelyunpleasant and often results in high cost and poor quality. Furthermore,the lay-up of F-R P material on vertical surfaces is difficult andshould be avoided.

E. Government regulations specify the following types of lifeboats:

l. Oar propelled (only if under 599 cubic feet capacity).

2. Propeller driven, hand gear operated (only if 600 to 1,000 cubicfeetcapacity).

3. Diesel engine driven (any size to 36 feet in length).

4. Type 3 with radio cabin. In a lifeboat of this invention thedesignation of any of the above named types need not be made until aftercompletion of all assembly except thwart platforms. Even a later changefrom one type to another, if required, is a minor operation. This isobviously of advantage to the lifeboat builder.

F. In the past, the pre-fabrication of parts was not popular becauselifeboat sizes were not standardized. This has now been corrected. Thelifeboat dimensions in way of the ships davits and the arm dimensions ofthe davits have now been published in a standard lifeboat code by atechnical committee, members of which are appointed by several elementsof the shipping and shipbuilding industries and by the Government.

Essential to this invention is the three-way split method offabrication, along center line of lifeboat and hoisting bulkheads,allowing two sides, two fairwater ends and a keel to be pre-fabricatedand stored to await final assembly. This method of fabrication ispossible only because the parts, as described, cannot warp, sag orbecome otherwise misshapen.

The outer hull side, inner hull and gunwale brace panel, having beenfabricated, in individual molds, are interchangeableend for end and areclamped as a lifeboat side unit in a rotating rig with trunnions onpedestals at each end. Thus, the side unit may be turned in any positiondesired and all plastic lay-up and assembly work can be accomplished byoperators standing on the shop floor. Rotating rigs can be used to greatadvantage in the lay-up operation of parts of this invention but theyare not claimed as a novelty.

. There are other advantages of the three-way split type of lifeboatassembly. For instance, it may be decided that the main plasticproduction occur at a plant which is located away from the finalassembly plant. In the past it was customary that lifeboats befabricated at one location. Today, due to my sub-assembled lifeboat sideunit, which will not twist, warp or sag, it is feasible to have allprimary lay-up of fiberglass-reinforced plastic done by a reputablecompany which is better able to keep its highly experienced operatorsand specialized machinerybusy doing just such work in air conditionedshops. 7

Another feature of this invention relates to a hoisting gear arrangementwith simultaneous hook release at each end as it is installed in afiberglass-reinforced plas-,

tic lifeboat of this invention with three-way split feature offabrication.

The method of installation of a hoisting gear in present-day plasticlifeboats is still very much as illustrated in FIG. 6 of Elling priorU.S. Pat. No. 2,478,042; that is, it is still mounted on a verticallypositioned rectangular bar having a hook-body with a clevis-type back, ahook pin at its top through the clevis parts and a spoon-like platesupport under the keel. Such an arrangement necessitates: l twouniversal joints at each end of the boat instead of one and (2) thepositioning of the fore and aft release rod at lower thwart levelinstead of top thwart level which makes the operation of the hand leverover a swing of degrees difficult. Therefore, it is a major object ofthis invention to provide means for a reliable, direct hull connectionof the hoisting gear. The three-way split method of manufacture allowsthe simple one-piece construction of the outer hull half with the splithoisting bulkhead as an integral part, of which the required factor ofsafety of the hoisting gear connections can easily be calculated.

The inner hull side may be readily inserted in an outer hull side andmay later, after completion of subassembly with all other lifeboat sideparts, be joined together with the keel and with the similarly completedopposite side. The inner hull, all in one piece with three knuckles,comprises three straight, flat panels and a keel flange, terminating attheir junction with the curved outer hull.

It is a further object of this invention to provide a new flexiblegunwale bracing consisting of a flat longitudinal gunwale brace panel,which forms a triangular section with the upper part of the outer hullon each side of the lifeboat. The upper part is flanged and bonded tothe underside of the gunwale top and the lower edge butts against theinside reinforcement of the outer shell along the upper seat panel ofthe inner hull. A Coast Guard slamming test is required during which thelifeboat is swung against a ship's hull from a distance of ten feet.Because of the existence of a one-inch nosing projection near thegunwale top there will take place, during the test, somebending in theouter shell at the junction with the inner hull but no breakage willoccur because the normally installed rigid braces from gunwale to seathave been eliminated and F-R P strips, tapered from the point of thethree-part junction, are being used to gain flexibility.

Lifeboats are suspended from ships davits with the hoisting points neartheir ends and, because of the great human load during lowering, thereis need for longitudinal strength. The lifeboat of this invention is anideal girder with the extreme top fibers in the gunwale sections andwith the extreme bottom fibers in the keel section. It is only necessaryto provide for strong braces and spreaders to keep above named bottomand top sections rigidly in place which is accomplished by inner hull,outer hull and transverse thwarts; All of which are forminga triangularbox section. The inner hull, and the outer hull deep-bellied containersare again held in their position by poured-in-place foam with goodadhering quality and with 30 to 50 PSI compressive and tensile strength.

The three-way split sub-assembly feature servesthe purpose of divorcingthe structurally unimportant fairwater ends from the hull structure andhoisting structure which, together, are a structural entity bythemselves. The fairwater ends, completely filled with poured-in-placefoam, are constructed with a thin F-R P shell without stem, sternpost orother stiffeners and thereby saving weight. Since the vertical part ofthe hoisting bulkhead is in exact line with the center of the shipsdavit, the required chafing guard on the outer hull in way of the davitarms will cover the seam between fairwater end and the outer hullrecess.

All lifeboats aboard ships are secured to each davit by over thegunwales, past the keel cables which are tightened, sometimes to excess,by turnbuckles. It is obvious that a lifeboat must be quite strongtransversely to withstand the stress in way of these holding cables inadverse weather. The following parts of this invention will fill thisneed: A double-thick hoisting bulkhead, the ends of gunwale brace panel,an extended transverse cambered deck with doubling recess, a doublingrecess in each outer hull-half with the edge area of the fairwater and achafing guard doubling between keel and gun- Wale.

Another object of this invention is to provide, in afiberglass-reinforced plastic lifeboat, for a strong outer hull withoutadding excessively to the thickness of the shell. However, the shell ofthis invention will still be capable of withstanding the drop of a fullyloaded lifeboat into the water from a height of ten feet. On each sidethere are two sectionally half round grooves and one rounded offset,positioned longitudinally and at about equal distance from one anotherbetween gun- Wale and keel, extending about two-thirds the length of thelifeboat. The offset groove has been chosen to facilitate easy moldrelease which must be sideways because of the flanged gunwale top. Thegrabrails, in themselves not a part of this invention, have theirsupports inserted in parts of these grooves. The combination of groovesin the outer hull and the presence of pouredin-place urethane foam overthe area of the outer shell within the ends of the inner hull makespossible the elimination of all inside framing.

It is an object of this invention to provide means in afiberglass-reinforced plastic lifeboat for a combination of transverseand lateral strength (the latter to withstand a 200 pound sandbag dropfrom a 6-foot height on the thwarts) with stability-producing storagefacility near the keel, of a total of 1 1 pounds of water, milk andprovisions, all in cans, for each passenger, under relatively thinthwarts which serve as fixed covers for deep bellied tanks.

A further object of this invention is the combination of a manual seacock water inlet to increase stability in the lifeboat and the use ofthe same sea cock for draining excess water through a manually tendedrubber hose. In the first instance, a water load right above the keelcannot splash sideways and will assure enough stability for the lifeboatto remain upright and in the second instance, by lifting the rubber hoseend to the water level when sea cock is open, it will start draininguntil the outside level is reached.

Plastic lifeboats embodying this invention are shown in the accompanyingdrawings, of which:

FIG. 1 is a perspective view of the left side of a diesel drivenlifeboat with parts cut off along the longitudinal center line. Thefairwater ends of the lifeboat have been omitted in this view for thepurpose of clarity.

FIG. 2 is a fragmentary horizontal section on the line 1 1 of FIG. 1,showing the rabbet-like recess and demonstrating great transversestrength concentration in way of ships davits.

FIG. 3 is an enlarged scale view on the line 2 2 of FIG. 9.

FIG. 4 is an enlarged scale view on the line 3 3 of FIG. 10. The gearunit base plate of FIG. 4 is identical in size to the gear unit baseplate in FIG. 3.

FIG. 5 is a transverse vertical section on the line 4 4 of FIG. 1,except that the release rod is shown in FIG. 5 at center line. FIG. 5also demonstrates schematically the sequence of foaming the inner hullarea and the gunwale area without leaving air pockets, easilyaccomplished by rotating the lifeboat-half as described elsewhere.

Background of FIG. 5 is a view on the line 5 5 of FIG. 3.

FIG. 6 is an enlarged scale gunwale section of FIG. 5, showing securingclamp bolts which also serve as oarlock sockets and sockets foranti-exposure cover stanchions.

FIG. 7 is an enlarged scale keel section of FIG. 5 showing l theattachment of the boat hulls to the keel and (2) the recesses in theinner hull for two different fittings described elsewhere herein, thetwo fittings are secured to the inside of the outer hull but notnecessarily at the same longitudinal position.

F [G8 is a transverse vertical section on the line 6 6 of FIG. 1. Thethwart in way of the engine enclosure is shown slightly raised to showthe possibility of installing a larger engine, if required. The completeengine unit with enclosure and brackets may be exchanged for a manuallyoperated propelling gear unit without any change in the basic lifeboatstructure. In a similar way and with similar brackets a prefabricatedradio cabin may be installed in the location indicated in FIG. 10.

FIG. 9 is a plan view outline of lifeboat as in FIG. 5 but with its gearrelease rod along the center line.

FIG. 10 is a plan view of a lifeboat as in FIG. 8 but with its gearrelease rod off the center line and just clear of the engine enclosureor of the radio cabin or both.

FIG. 11 is a schematic arrangement of precision made parts lendingthemselves to easy assembly. All parts are interchangeable.

FIG. 12 is a bottom view of the outer hull halves showing the shellgrooves and the hoisting bulkhead seam which is covered by the boltwasher plate.

FIG. 13 is an enlarged scale section on the line 7 7 of FIG. 12 with endview and plan view of a metal hand raii stanchion.

FIG. 14 is a perspective view of lifeboat parts from midship towardsend, showing one inner hull, one gunwale brace panel and one fairwaterend, all in proximate position to one another.

Referring to illustrated structure by reference numbers, thefiberglass-reinforced plastic (F-R P) outer hull shell 15 extends in asingle piece on each side of the lifeboat between bulkhead center linebutt aft 16 and bulkhead center line butt forward 17 and between inboardedge of gunwale top 18 and underside of keel 19. The curvature of theouter hull is conventional except that, at the hoisting points 20, theouter hull turns squarely towards the center line to abut at 16 and at17 with the ends of the opposite identical lifeboat half, thus forming atransversely straight hoisting bulkhead 21 which has a transverseknuckle at 22.

An additional departure from the conventional outer hull are the grooves23 and the rounded offset 24 positioned at about equal distance betweengunwale and keel and having a length of about two-thirds the length ofthe lifeboat. The nosing projection 25 is a gunwale combinationextending toward each end just short of imaginary transverse lines athoisting points 20. The detail of grabrail stanchion 26 and the grabrailrod 27, which are not part of this invention, has been shown todemonstrate the suitability of grooves.

The fiberglass-reinforced plastic (F-R P) inner hull 29 extends in asingle straight piece, in fore and aft direction on each side of thelifeboat, between the points of intersection 30 with the curved outerhull 15. The inner hull 29, in a zigzag form extends transversely fromunderside of keel 19 to its upper edge which butts against the outerhullreinforcement 46, at which point the inner hull is supported bylongitudinal F-R P stringer 38 and thwart brace 31. Longitudinalhardcore laminated thwart support stringers 33 with backing stringers 34arepositioned just belowupper and lower riser panel knuckles 32. Thekeel flange knuckle 32 of theinner hull fits snugly over the keel flangeknuckle 32 of the outer hull.

The fiberglass-reinforced plastic (F-R P) gunwale brace panel 35 extendsin a single piece on each side of the lifeboat longitudinally betweenend points 36 which are approximately on an imaginarytransverse linethrough hoisting points 20, at each end. The upper part is rounded at 37and flanged under gunwale top 18 t and the lower edge is locked in thecorner formed by the inner hull 29 and outer hull reinforcement strip46.

Full enclosure is assured by F-R P bonding strip 28. Additional strengthis provided by a combination of metal sleeve nuts 39 and hollow threadedbolts 40 which have a slanted head with tie rope eyes 41. The hollowbolts are suitable for oarlock sockets and for cover stanchion sockets.

The fiberglass-reinforced plastic (F-RP) fairwater end 42 with fairwaterdeck 42A at each end of the lifeboat is molded to a precise fit in therabbet-like recess 43 which is formed along the perimeter of thehoisting bulkhead in the deck extension 18A and in the side shells ofouter hull 15. After assembly, inside space is filled with foam 47through vent and fill holes 48. The lower part of hoisting bulkhead 21below knuckle 22 is vertical and in line with hoisting points 20 andwith the center of the davit arm rest 44. The multi-purpose F-R used forthe total inside areas of each hoisting bulkhead 21 and for strip 46 tocover the recess seam and to protect the outer hull against chafing inway of the davit arm rest '44.

The filling of hollow spaces between outer hulls 15 and inner hulls 29and between outer hulls 15 and gunwale brace panels 35 withpoured-in-place urethane foam 47 requires a set-up and proceduresuitable for the avoidance of air pockets when pouring foam and forallowing operators to remain on the shop floor during such operation.This is made possible by a threeway split lifeboat assembly method madeobvious by the following described procedure. A lifeboat-half thus fardescribed is clamped in a rotating rig with trunnions on pedestals ateach end and by simple hand rotating of the lifeboat-half unit. Themachine mixed foam liquid is blown by a nozzle through fill and ventholes 48 with the rig turned so that foam part 47A is at the lowestposition, followed by 47B; the extreme ends may then be filled byraising one end after the other, always checking the vent and fill holes48. After a short wait, the rig is turned so that 47D is at the lowestposition, followed by 47E and then, after another short wait, turnedback to 47C and finally to 47F until all vent and fill holes showpositive escape of foam. In a similar way the space between outer hull15 and gunwale brace panel 35 is filled with foam. The vent and fillholes 48 are plugged with F-R P.

The fiberglass-reinforced plastic (F-R P) keel 49 extends in a singlepiece slightly beyond the hoisting bulkheads at each end of the boatwhere the straight underside of the keel 50 serves as lifeboat rest inships davit arms. The keel arms 51 are reaching up and are buttingagainst the center line seam of the bulkhead halves 21 and are securedby bolted angles 52.

The heads of bolts 53 are permanently attached to bolt-washer plate 54.The thread of bolts'55 is projecting inside of lifeboat for securingangles 52 and hoisting unit base plate 56. The latter has attached hookside plates 57, painter eye clip 58 and hook lock cup bearing 59.Movable parts of the lifeboat hoist gear and its manual simultaneousrelease gear at each end are: Hook 60, hook pin 61, hook lock cup 64,hook lock extension 65, universal joint 66, joint support and coverguard 67, release rod 68 and attached hand release lever 69. Parts 64,65 and 66 are permanently attached to one another. The distance 62between hoisting link 20 engaged by hook 60 and hoisting hook pin 61 iskept to a minimum for the purpose .of reducing, during the loweringoperation, the stress against the hook shank 63 making it easier to turnthe hook-lock cup 64 which has an open rim on one side. There is also,because of said reduced friction in the cup, less effort required on therelease lever 69 and, for the same reason, the release rod 68 can bereduced in size. The possibility of a sluggish hook release, which mightoccur if the lifeboat is swinging longitudinally, is prevented by alonger hook pin 61, projecting on each side so that the davit hoist link20 will bear on the projections of hook pin 61 and thereby force hook 60to swing open.

The double width seat platforms or upper thwarts 70 and 71 and the lowerthwarts 72 of hard-core laminated material are secured to longitudinalsupports 33. The upper thwarts 70 serve as air-tight covers for thefiberglass-reinforced plastic (F-R P) provision containers 73 and forthe fuel container 74. The thwart 71 is not attached to the engineenclosure 76 but it is increased in thickness and may have an offset71A, if required, to suit height of engine 75 and engine enclosure 76.

The engine shaft sleeve 78 is secured to side of keel arm 51. Doublethick upper end-thwarts 79 are bracketed to keel arm angles 52. Theengine 75 and engine enclosure 76 have permanently attached brackets 77connected to and supported by longitudinal stringers 33. The radio cabin81 is bracketed in a similar way to stringers 33.

Each inner hull-half 29 is provided with a recess 80 having a bottom 80Ato accommodate a drain fitting 82 with a rubber ball 83 in the outerhull-half 15 or, in the recess 80 of the identical opposite innerhull-half to accommodate a manual bilge water control sea cock 84 with ashort rubber hose 85.

I claim:

1. In a lifeboat of fiberglass-reinforced plastic, an outer hull-half inone piece on each side symmetrical and identical with opposite outerhull-half, each fabricated from a single symmetrical mold thus allowingthe turning of one of two outer hull-halves end for end for using one onleft side and one on right side, each of said hull-halves curvinginboard towards the ends and at hoisting points squarely turning inboardto a meeting with the opposite hull-half at center thus forming at eachend a flat but knuckled hoisting bulkhead with the knuckle at about halfits height, a longitudinally straight knuckled inner'hull-half in onepiece on each side and each fabricated from a single symmetricalmoldthus allowing the turning of one of two inner hullhalves end for end forinstalling one in left outer hullhalf side and one in right outerhull-half side, each comprising a longitudinal bottom keel flange, alower riser panel, a middle riser panel, and a top seat panel, allextending parallel to the center line and terminating where each panelintersects with the curved outer hull, said seat panel and ends of riserpanels bonded to inside of outer hull by F-R P strips, a longitudinallaminated hard-core thwart support stringer with backing stringer bondedto inner hull below upper knuckle of each riser panel for support ofupper and lower thwarts, a gunwale brace panel in one piece in each ofsaid outer hullhalves and each fabricated from a single symmetrical moldthus allowing the turning of one of two gunwale brace panels end for endfor installing one in left outer hull-half side and one in right outerhull-half side,

extending between the gunwale ends and following its curve in inclinedposition with its lower edge at connection of seat panel to'outer hulland with an outwardly flanged top bonded to underside of outer hull topflange or gunwale top, a double width flat F-R P keel interchangeableend for end positioned vertically in a single piece between bulkheads ateach end with its lower part bonded between inner hull and outer hullflanges, an arm of the keel at each end reaching up to butt against thecenter line seam of the hoisting bulkheads which are part of the outerhull-halves and attached by bolted angles on each side, underside ofkeel at each end below the bulkheads made suitable to serve as keelrests on davit arms when in stowed position, a symmetrical saucer-likeshaped fairwater boat end attached to each end of the outer hull bybonding in a rabbet-like recess along the perimeter of the said hoistingbulkheads, three or more laminated hard-core double width seat platformsor thwarts positioned athwartsl'iip about two and one half feet apartand their ends secured to said upper thwart support stringers formingthe top of deep-bellied F-R P provision containers, one hoisting andsimultaneous release gear unit with interchangeable unit base platestraddling the said bulkhead seam of the diagonally positioned upperpart of said hoisting gear bulkhead on each end of the lifeboat, hollowspace between said outer hullhalves and said inner hull-halves andbetween fairwaters and hoisting bulkheads and between said gunwale bracepanels and outer hull-halves filled with light poured-in-place urethanefoam.

2. In a lifeboat of fiberglass-reinforced plastic as in claim 1, havingsaid hoisting bulkhead vertical in the lower part and diagonallyinclined away from midship in the upper part with the top flangingtowards amidship to form a cambered deck extension which is in a fairline with the gunwale top on each side and with the deck of saidfairwater, a rabbet-like recess along the perimeter of the hoistingbulkhead-halves at sides and top to accommodate the open rim area of thefairwater boat ends, a bolt washer plate straddling the butt seam of thebulkhead-halves'on the far side from midship with weldedbolt heads whosethreads are projecting inside of the lifeboat.

3. In a lifeboat of fiberglass-reinforced plastic as in claim 1, saidsymmetrical saucer-like shaped fairwater at each end of the lifeboathaving a curved pointed end two curved sides and a cambered deck and itsopen rim area being attached by bonding to the outer hull in arabbet-like recess along perimeter of said hoisting bulkheads, saidfairwater having a slot opening at its lower pointed end allowinginsertion of keel for forming davit rest, an anti-chafing doubling stripof F-R P outside of said outer hull and of fairwater rim centered inline with lower part of hoisting bulkhead and covering the recess seamon each side of the lifeboat from keel to gunwale.

4. In a lifeboat of fiberglass-reinforced plastic as in claim 1, saidsymmetrical outer hull-half having a bottom keel flange and a gunwaletop flange with the latter in combination with a half-round outboardnosing projection extending longitudinally just short of hoistingbulkheads at each end, two longitudinal half-round grooves and oneoffset groove with rounded corners for hull stiffening and for secureand simple installation of hand grabrails in each outer hull-halfpositioned at equal distance between gunwale and keel and having alength of about two-thirds the distance between lifeboat ends, saidoffset groove to facilitate necessary sideways mold release, a recess insaid lower riser panel of inner hull adjacent to said keel flanges oneach side and of a size to suit the installation of a standard one inchsea cock flange or of a drain fitting flange with the recess bottombonded to the inside of said outer hullhalf.

5. In a lifeboat of fiberglass-reinforced plastic as in claim 1, saidinner hull-half seat panel positioned about 10 inches below gunwale tophaving its outer edge terminating where it intersects with curved outerhull, said gunwale brace panel forming a triangular hollow section withgunwale top flange and upper part of outer hull, bonded together andfilled with light poured-inplace urethane foam, a number ofself-draining metal socket tubes positioned nearly vertical through saidtri angular section having flanged heads and inside thread at lower endsengaging thread matching hollow bolts with slanted heads firmly holdinggunwale top and gunwale brace panel together thereby adding additionalstrength and for use as sockets for oarlocks and cover stanchions.

6. In a lifeboat of fiberglass-reinforced plastic as in claim 1, saidtop seat panel of inner hull-half positioned about ten inches belowgunwale top at midship and terminating where it meets with the curvedouter hull, longitudinal laminated hard core thwart support stringer andbacking stringer bonded to said inner hull below upper knuckle of eachriser panel one for upper thwarts and one for lower thwarts, three ormore laminated hard core double width upper seat platforms or thwartspositioned athwartship about two and a half feet apart and their endssecured to said upper thwart support stringers and forming the top ofairtight deep-bellied F-R P provision containers which are formed sothat they have contact with said keel and with said support stringer forlower thwarts providing girder bracing between extreme top fibers in thegunwale sections and extreme bottom fibers in the keel section.

7. In a lifeboat of fiberglass-reinforced plastic as in claim 1, saidknuckled hoisting bulkhead whose upper part above said knuckle leaningaway from midship, a hoisting gear unit base plate positioned above saidbulkhead knuckle, a flat swinging hoisting hook engaged by a hook pin intwo side bracket plates which are attached to said gear unit base plate,a hook lock extension which is part of a single universal joint at eachend in the center of the lifeboat, a hook-lock cup bearing attached bybracket to said gear unit base plate and engaging a hook lock cup whichis attached to upper end of said hook lock extension and has a cutawayrim on one side, a rotating horizontal release rod extending at upperseat level along the center line of the lifeboat between said universaljoints and having a single hand operated release lever attached forsimultaneous release of both hooks.

8. In a lifeboat of fiberglass-reinforced plastic as in claim 7,wherein: said rotating horizontal release rod extending at upper seatlevel and about fourteen inches off center line of the lifeboat betweentwo universal joints, each bracketed to reinforced end thwarts and saidhorizontal release rod having a single hand operated lever attachedforsimultaneous release of both hooks, at each end a swinging hoisting hookwhich is flat in its upper part with hook bight in vertical line withlower part of said hoisting bulkheads and engaged by a hook pin, twohook side bracket plates which are attached to said gear unit baseplate, a hook locking tail or shank pointing down to one side indirection toward said hook lock extension which is part of the singleuniversal joint at each end of the lifeboat, a hook lock bearingattached by bracket to said gear unit base plate and engaging hook lockcup being attached to said hook lock extension and having a cut-away rimon one side and opposite rim to have its center when in locked positiondirectly in line with center of upper part of hook.

1. In a lifeboat of fiberglass-reinforced plastic, an outer hull-half inone piece on each side symmetrical and identical with opposite outerhull-half, each fabricated from a single symmetrical mold thus allowingthe turning of one of two outer hull-halves end for end for using one onleft side and one on right side, each of said hull-halves curvinginboard towards the ends and at hoisting points squarely turning inboardto a meeting with the opposite hull-half at center thus forming at eachend a flat but knuckled hoisting bulkhead with the knuckle at about halfits height, a longitudinally straight knuckled inner hullhalf in onepiece on each side and each fabricated from a single symmetrical moldthus allowing the turning of one of two inner hull-halves end for endfor installing one in left outer hullhalf side and one in right outerhull-half side, each comprising a longitudinal bottom keel flange, alower riser panel, a middle riser panel, and a top seat panel, allextending parallel to the center line and terminating where each panelintersects with the curved outer hull, said seat panel and ends of riserpanels bonded to inside of outer hull by F-R P strips, a longitudinallaminated hard-core thwart support stringer with backing stringer bondedto inner hull below upper knuckle of each riser panel for support ofupper and lower thwarts, a gunwale brace panel in one piece in each ofsaid outer hull-halves and each fabricated from a single symmetricalmold thus allowing the turning of one of two gunwale brace panels endfor end for installing one in left outer hull-half side and one in rightouter hull-half side, extending between the gunwale ends and followingits curve in inclined position with its lower edge at connection of seatpanel to outer hull and with an outwardly flanged top bonded tounderside of outer hull top flange or gunwale top, a double width flatF-R P keel interchangeable end for end positioned vertically in a singlepiece between bulkheads at each end with its lower part bonded betweeninner hull and outer hull flanges, an arm of the keel at each endreaching up to butt against the center line seam of the hoistingbulkheads which are part of the outer hull-halves and attached by boltedangles on each side, underside of keel at each end below the bulkheadsmade suitable to serve as keel rests on davit arms when in stowedposition, a symmetrical saucer-like shaped fairwater boat end attachedto each end of the outer hull by bonding in a rabbet-like recess alongthe perimeter of the said hoisting bulkheads, three or more laminatedhard-core double width seat platforms or thwarts positioned athwartshipabout two and one half feet apart and their ends secured to said upperthwart support stringers forming the top of deep-bellied F-R P provisioncontainers, one hoisting and simultaneous release gear unit withinterchangeable unit base plate straddling the said bulkhead seam of thediagonally positioned upper part of said hoisting gear bulkhead on eachend of the lifeboat, hollow space between said outer hull-halves andsaid inner hull-halves and between fairwaters and hoisting bulkheads andbetween said gunwale brace panels and outer hull-halves filled withlight poured-in-place urethane foam.
 2. In a lifeboat offiberglass-reinforced plastic as in claim 1, having said hoistingbulkhead vertical in the lower part and diagonally inclined away frommidship in the upper part with the top flanging towards amidship to forma cambered deck extension which is in a fair line with the gunwale topon each side and with the deck of said fairwater, a rabbet-like recessalong the perimeter of the hoisting bulkhead-halves at sides and top toaccommodate the open rim area of the fairwater boat ends, a bolt washerplate straddling the butt seam of the bulkhead-halves on the far sidefrom midship with welded bolt heads whose threads are projecting insideof the lifeboat.
 3. In a lifeboat of fiberglass-reinforced plastic as inclaim 1, said symmetrical saucer-like shaped fairwater at each end ofthe lifeboat having a curved pointed end two curved sides and a cambereddeck and its opeN rim area being attached by bonding to the outer hullin a rabbet-like recess along perimeter of said hoisting bulkheads, saidfairwater having a slot opening at its lower pointed end allowinginsertion of keel for forming davit rest, an anti-chafing doubling stripof F-R P outside of said outer hull and of fairwater rim centered inline with lower part of hoisting bulkhead and covering the recess seamon each side of the lifeboat from keel to gunwale.
 4. In a lifeboat offiberglass-reinforced plastic as in claim 1, said symmetrical outerhull-half having a bottom keel flange and a gunwale top flange with thelatter in combination with a half-round outboard nosing projectionextending longitudinally just short of hoisting bulkheads at each end,two longitudinal half-round grooves and one offset groove with roundedcorners for hull stiffening and for secure and simple installation ofhand grabrails in each outer hull-half positioned at equal distancebetween gunwale and keel and having a length of about two-thirds thedistance between lifeboat ends, said offset groove to facilitatenecessary sideways mold release, a recess in said lower riser panel ofinner hull adjacent to said keel flanges on each side and of a size tosuit the installation of a standard one inch sea cock flange or of adrain fitting flange with the recess bottom bonded to the inside of saidouter hull-half.
 5. In a lifeboat of fiberglass-reinforced plastic as inclaim 1, said inner hull-half seat panel positioned about 10 inchesbelow gunwale top having its outer edge terminating where it intersectswith curved outer hull, said gunwale brace panel forming a triangularhollow section with gunwale top flange and upper part of outer hull,bonded together and filled with light poured-in-place urethane foam, anumber of self-draining metal socket tubes positioned nearly verticalthrough said triangular section having flanged heads and inside threadat lower ends engaging thread matching hollow bolts with slanted headsfirmly holding gunwale top and gunwale brace panel together therebyadding additional strength and for use as sockets for oarlocks and coverstanchions.
 6. In a lifeboat of fiberglass-reinforced plastic as inclaim 1, said top seat panel of inner hull-half positioned about teninches below gunwale top at midship and terminating where it meets withthe curved outer hull, longitudinal laminated hard core thwart supportstringer and backing stringer bonded to said inner hull below upperknuckle of each riser panel one for upper thwarts and one for lowerthwarts, three or more laminated hard core double width upper seatplatforms or thwarts positioned athwartship about two and a half feetapart and their ends secured to said upper thwart support stringers andforming the top of airtight deep-bellied F-R P provision containerswhich are formed so that they have contact with said keel and with saidsupport stringer for lower thwarts providing girder bracing betweenextreme top fibers in the gunwale sections and extreme bottom fibers inthe keel section.
 7. In a lifeboat of fiberglass-reinforced plastic asin claim 1, said knuckled hoisting bulkhead whose upper part above saidknuckle leaning away from midship, a hoisting gear unit base platepositioned above said bulkhead knuckle, a flat swinging hoisting hookengaged by a hook pin in two side bracket plates which are attached tosaid gear unit base plate, a hook lock extension which is part of asingle universal joint at each end in the center of the lifeboat, ahook-lock cup bearing attached by bracket to said gear unit base plateand engaging a hook lock cup which is attached to upper end of said hooklock extension and has a cut-away rim on one side, a rotating horizontalrelease rod extending at upper seat level along the center line of thelifeboat between said universal joints and having a single hand operatedrelease lever attached for simultaneous release of both hooks.
 8. In alifeboat of fiberglass-reinforced plAstic as in claim 7, wherein: saidrotating horizontal release rod extending at upper seat level and aboutfourteen inches off center line of the lifeboat between two universaljoints, each bracketed to reinforced end thwarts and said horizontalrelease rod having a single hand operated lever attached forsimultaneous release of both hooks, at each end a swinging hoisting hookwhich is flat in its upper part with hook bight in vertical line withlower part of said hoisting bulkheads and engaged by a hook pin, twohook side bracket plates which are attached to said gear unit baseplate, a hook locking tail or shank pointing down to one side indirection toward said hook lock extension which is part of the singleuniversal joint at each end of the lifeboat, a hook lock bearingattached by bracket to said gear unit base plate and engaging hook lockcup being attached to said hook lock extension and having a cut-away rimon one side and opposite rim to have its center when in locked positiondirectly in line with center of upper part of hook.